So I'm on my third install of Windows Vista Beta 1 (fourth, if you include installing on Virtual PC), and I figured it's probably a good time to share some of my experiences.
On older hardware:
On more recent (but still not brand-new) hardware:
On a less than 1 year-old laptop:
One other note...I found a site called http://www.tweakvista.com/, which has some Windows Vista tips, as well as a downloadable utility that allows you to tweak some of the settings for the Aero interface. One that I find neat is the ability to use the Shift key to slow down the window animations. This allows you to see more clearly exactly what's going on. A novelty, to be sure, but fun.
Although I did take the time to install the runtime components for Avalon and Indigo, as well as the WinFX SDK, on a couple of these machines, I have not yet taken the time to install Visual Studio 2005. Thankfully, someone pointed out the a blog entry from Dave Glover with a workaround to one of the issues that can occur with the install, so hopefully when I get to that point, it'll go as smoothly as the Windows Vista install itself.
While I approached the dual-boot installs with some trepidation (I'm generally somewhat risk-averse, but I really need to start getting up to speed on Indigo and Avalon, and where better to do that than on Windows Vista?), my experience with Windows Vista so far has left me pretty impressed. As mentioned above, the usual warnings and caveats that go with any beta still apply, but if you're feeling frisky, and have a machine you're willing to experiment on, you might just want to check it out.